JP2001018379A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance durability of an ink image by providing a fluid injection means for coating the image with a fluid for forming a transparent film for protecting the image. SOLUTION: The ink jet printer comprises ink jet print heads 31 to 34 for injecting inks to an ink receiver 80 such as a recording sheet or the like and a print head driving electronic circuit 30. Further, the printer comprises a fluid injection head 123 for transferring a polymer fluid to an ink image, and a fluid injection driving electronic circuit 60, thereby supplying the transparent polymer fluid from a fluid container 44 to the head 123. The fluid is injected as a droplet 125 onto the image 140, and an overcoating film is formed on the receiver 80. A computer 20 controls the circuit 60. Thus, overcoating is conducted without contact with the image with a coating unit, only a necessary area is coated with the fluid, and the head 123 can be simultaneously moved with the heads 31 to 34 by the same transferring mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet printing apparatus for providing an ink image having a protective film.

[0002]

BACKGROUND OF THE INVENTION U.S. Patent Application Serial No. 08/83, filed September 19, 1997, entitled "Inkjet Printing by Radiation Treatment" by Xin Wen.
U.S. Patent Application Serial No. 09 / 325,078, filed by Shin Wen, entitled "Apparatus for Forming Textured Layers on Images" And the disclosures of which are incorporated herein by reference.

[0003] Inkjet printing has become a prominent competitor in the digital output arena due to its non-impact, low noise, and compatibility with plain paper. Ink jet printing removes the complexity of transferring and fixing toner in electrophotography and the contact pressure of the printing interface in thermal resistive printing technology. Ink jet printing mechanisms include continuous ink jet or drop-on-demand ink jet. 1
U.S. Pat. No. 3,946,398, issued to Kyser et al. In 970, discloses a method of applying a high voltage to a piezoelectric crystal, causing the crystal to bend, and applying pressure to an ink container. A drop-on-demand type ink jet printer that ejects droplets on demand is disclosed. Piezoelectric inkjet printers can also utilize piezoelectric crystals in push, shear, and squeeze modes. European Patent Application Publication EP8
No. 27833A2 and International Publication WO98 / 0
No. 8687 discloses a piezoelectric ink jet printer head device with reduced crosstalk between channels, improved ink resistance, and the ability to vary and eject ink drops.

[0004] US Patent No. 4,723,129 to Endo et al. Applies a power pulse to an electric heater in thermal contact with aqueous ink in a nozzle. Discloses an electrothermal drop-on-demand type inkjet printer. The heat from the electric heater creates a vapor bubble in the ink that causes the ink droplets to be ejected from a small opening along the edge of the heater base. This technology is known as Bubble Jet (registered trademark of Canon Inc., Japan).

US Pat. No. 5,635,969 discloses that prior to printing an ink image on an ink receiver,
A printhead for conditioning a receiver by injecting processing fluid to the receiver is disclosed. The processing fluid on the receiver then immobilizes the ink pixels printed on the receiver,
It improves the shape of the dots, thereby improving the quality and stability of the print.

[0006]

[0006] Ink jet images often have problems with image durability. The durability of an image is determined by its resistance to physical wear, water (ie,
(Fastness to water), light fade (fastness to light) and environmental conditions (such as oxidation), and stability to stains such as fingerprints on images. A traditional way to increase the durability of an ink jet image is to glue the sheets stacked on the ink image using a laminator. The laminate sheet is pre-covered with a layer of adhesive.
Typically, pressure and heat are required to bond the laminate and the ink receiver together.

[0007] The lamination method has several disadvantages. First
In addition, laminated sheets significantly increase the cost of the media per unit area. Second, laminating equipment is expensive, and sometimes more expensive than the inkjet printer itself. Third,
Laminations tend to delaminate over time or due to physical or thermal disturbances.

It is an object of the present invention to provide an ink jet printing apparatus that produces an ink image on a receiver with enhanced image durability.

[0009]

SUMMARY OF THE INVENTION An inkjet printing apparatus according to the present invention is an inkjet printing apparatus for forming a durable ink image on a receiver in response to a digital image, comprising: At least one inkjet printhead adapted to eject to a receiver; and b) operating the inkjet printhead to eject ink to the receiver to form an ink image in response to the digital image. And c) fluid ejection means for applying a fluid on the ink image to form a transparent solid continuous film for protecting the ink image.

[0010] The ink jet printing apparatus according to the present invention is an ink jet printing apparatus for forming a durable ink image on a receiver in response to a digital image, and a) ejecting ink to the receiver. At least one inkjet printhead adapted to: b) operate the inkjet printhead for ejecting ink to the receiver to form an ink image in response to the digital image; c. A) a fluid ejection means for applying a polymer fluid onto said ink image, said polymer fluid forming a transparent solid continuous polymer protective film for protecting said ink image.

Further, the ink jet printing apparatus according to the present invention is an ink jet printing apparatus for forming a durable ink image on a receiver in response to a digital image, and a) ejecting ink to the receiver. A first inkjet printhead adapted to eject a polymer fluid to the receiver, and b) the first inkjet printhead and the second fluid ejection head, Means for simultaneously moving across the ink receiver; c) operating the first inkjet printhead to eject ink to the receiver at different locations on the receiver to form ink pixels; Means for forming an ink image in response to the image; Activating the second fluid ejection head for applying a polymer fluid onto the pixels formed by the jet print head, wherein the polymer fluid is a transparent solid continuous polymer protection film for protecting the ink image. And means for forming

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention relate to an inkjet printing apparatus that can provide improved durability of an ink image. In the present invention, the term "durability" refers to durability against physical abrasion, water (ie, fastness to water), fading by light (ie, fastness to light) and environmental conditions (such as oxidation), and Refers to the stability against stains such as fingerprints on images.

Referring to FIG. 1, an inkjet printing apparatus 10 includes a computer 20, control electronics 25, printhead drive electronics 30, black ink (K), cyan ink (C), magenta ink (M), and yellow ink. The drawing includes inkjet print heads 31 to 34 for printing (Y) and a plurality of ink containers 40 to 43 for supplying each color ink to the print heads 31 to 34. The print heads 31 to 34 are fixed to a holder 45, and the holder 45 can be translated by a print head translation motor 71 along a slide rail 54 in a high-speed scanning direction (indicated by an arrow in FIG. 1). . The sliding rail 54 is supported by a support member 55. The print heads 31 to 34, the fluid ejection head 123, and the holder 45 are transported by some mechanisms shown in FIG. In particular, the belt 56,
Pulley mechanism 57 and print head translation motor 71
Is illustrated. The printhead translation motor 71 can be a stepping motor, or alternatively a DC motor with a servo system. The fluid ejection head 123, in a preferred embodiment, is a wicking arrangem that propagates the ink by application rollers, spray bars, or capillary action.
It will be appreciated that other arrangements such as ent) may be used.

The inkjet printing apparatus 10 also includes a receiver transport motor 70, an ink receiver 80 such as a recording paper,
And a platen 90. The receiver 80 is a platen 90
Supported by The receiver transfer motor 70 is
The ink receiver 80 and the inkjet print heads 31 to 34 are relatively moved by using a roller 65 that moves the receiver 80 in a low-speed scanning direction orthogonal to the high-speed scanning direction. It will be appreciated that both receiver transport motor 70 and printhead translation motor 71 are bidirectional so that printheads 31-34, fluid ejection head 123, and receiver 80 can return to their initial positions.

The ink jet printing apparatus 10 further includes a fluid ejection drive electronics 60 and a fluid ejection head 123 for transferring a polymer fluid to an ink image, as described below. Fluid ejection head 123 contains a polymer fluid supplied by fluid container 44. The fluid ejection head 123 is preferably an ink jet print head as described in the background section of this application, and is either thermal ink jet or piezoelectric. When an inkjet printhead is used, the polymer fluid is applied onto the ink image 140 in a manner similar to inkjet printing.
Transferred as discretely ejected droplets 125 of polymer fluid. As a result, an overcoat film of polymer fluid is formed on the ink receiver 80. Computer 2
0 is the fluid ejection drive electronics 6 to determine the amount or location of polymer fluid applied to the ink receiver 80.
Control 0.

An advantage of embodiments according to the present invention is that the polymer overcoat does not involve contact of the applicator (eg, a contact roller) with the ink image. It has been discovered in the present invention that applying a polymer fluid while in contact with an ink image disturbs the ink image and causes ink quality degradation.

The polymer protective film may be formed uniformly throughout the ink receiver 80, or may be formed only on a portion of the ink receiver 80 where the ink image 140 (see FIG. 3) needs to be protected. it can. The use of a polymer fluid can be minimized by applying the fluid only to the required areas.

In FIG. 1, the fluid ejection head 123 is held by a holder 45,
It can be moved simultaneously by the same transfer mechanism as 1 to 34. Alternatively, the fluid ejection head 123 can be mounted on a separate transport mechanism. The fluid ejection head 123 also has a page-width nozzle so that the relative movement between the fluid ejection head 123 and the receiver 80 is provided by rollers 65 that move the receiver 80 under the operation of the receiver transfer motor 70. Can contain columns.

The operation of the ink jet printing device is illustrated in FIG. After printing starts (box 200), the ink image is first printed in box 210. An input digital image can be input or generated in computer 20. Digital image is computer 2
At 0, processed by image processing algorithms well known in the art, such as tone scale calibration, color conversion, halftone, ink rendering, and the like. Computer 20 sends a signal representing the digital image to printhead drive electronics 30 that prepares electrical signals according to the digital image data for printheads 31-34. During each printing pass, the computer 20 controls the control electronics 25 to control the receiver transport motor 70
Then, the print head translation motor 71 is operated. Under control of the computer 20, the receiver 80 is positioned in a swath of a plurality of image pixels to be formed, and the printhead translation motor 71 then moves the inkjet printheads 31-34 in the fast scan direction (see FIG. 1). (Shown). The print head driving electronic circuit 30 includes ink jet print heads 31 to 34
Is operated to eject the ink droplets 100 to the ink receiver 80 so as to form the ink pixels 110 on the ink receiver surface of the receiver 80. The ink image 140 is formed by a plurality of ink pixels 110. Each ink image 140 is typically formed by a plurality of printing passes.

Next, in box 220, a polymer overcoat film is applied over the ink image formed on ink receiver 80. Computer 2
0 controls the fluid ejection drive electronics 60, which determines the amount or location of the polymer fluid applied on the ink receiver 80. The polymer fluid is transferred to the ink image 140 as drops 125 of the polymer fluid discretely ejected by the fluid ejection head 123. On the ink receiver 80, the fluid droplets are spread and coalesced together to form a continuous fluid polymer overcoat film 130 on the ink receiver 80. The time delay between ejection of the ink drop 100 and the ejected drop of polymer fluid is controlled by the computer 20. Before the polymer fluid is applied, the ink pixels 110 are well absorbed into the ink receiver 80.

When reviewing the operation of the ink jet printing apparatus 10, the printhead electronics may include the ink pixels 11
At different locations on the ink receiver 80 forming a zero, the printheads 31-34 are operated to eject ink to the receiver and form a corresponding ink image 140 in response to the digital image. The fluid ejection drive electronics 60 operates a fluid ejection head 123 for applying a polymer fluid over the pixels formed by the first inkjet print head, which polymer fluid is a solid fluid for protecting the ink image 140. A transparent and continuous polymer protective film 150 is formed.

The polymer fluid can be an aqueous solution, polymer dispersion, polymer suspension, or polymer melt, such as a resin or latex solution. The polymer can include a single type of monomer or a copolymer of more than one type of monomer. The copolymerization can be blocked or randomized. As described below, the polymer can form a solid protective film when coagulated by polymerization. Also, the polymer fluid is
Stabilizers, surfactants, viscosity modifiers, wetting agents or diluents and other ingredients can be included. These additional components help the polymer fluid to be effectively ejected from the nozzles of the fluid ejection head 60, prevent the polymer fluid from drying out at the nozzles of the fluid ejection head 60,
The polymer fluid assists in proper coalescence on the ink image. Examples of polymer fluids tested in embodiments according to the present invention are described below.

In the present invention, the ink image 140 is a thermal inkjet HP 1200 Professional Series color printer (HP 1200 Professional Series Color Printer).
r printer) and Epson Color Stylus 900 printer with piezoelectric ink jet.
00 printer). Kodak Inkjet Photo Paper, Epson Glossy Film, High Quality Glossy Paper and Photo Paper
Paper) is used for the Epson Color Stylus 900 Printer. Kodak Inkjet Photo Paper (In
kjet Photo Paper), HP Premium Inkjet Glossy Paper, HP Premium Photo Paper, and HP Photo Paper are used in HP 1200 professional color printers.

An Epson Color Stylus 200 printer is used to inject the polymer fluid. The polymer fluid is applied to an ink cartridge for a piezoelectric printhead on an Epson Color Stylus 200 printer. A mass of foam material is placed in the cartridge to mitigate fluid movement during printing. Polymer fluid in aqueous solution,
It may include 5% or 10% AQ polymer, or 2% polyvinyl pyridine, or 5% polyurethane. Glycerol is also added to the polymer fluid as a humectant or diluent at a concentration of 5%.

The ink image 140 is sent to the receiver 80 by an Epson color stylus 900 printer and an HP 1200
Printed using a professional series color printer. An ink receiver 80 holding an ink image 140 was provided in an Epson color stylus 900 printer. The image files were designed on a computer. The image contained at least one region of uniform density. The image file was sent to an Epson Color Stylus 900 printer. The polymer fluid described above was ejected by a fluid ejection head 123 (which is a piezoelectric printhead) to form a wet polymer overcoat film 130 over the ink image 140 in response to the image file. The position and thickness of the polymer overcoat film 130 was controlled by the design of the image. For example, the coverage of one or two single layers of polymer fluid was overcoated on the ink image. Also, the printing resolution (dots per inch), the number of fluid ejection droplets 123 per pixel, the printing speed, and the volume of droplets for polymer fluid ejection were varied.

The formation of a solid polymer protective film 150 with a fluid polymer overcoat film is shown in box 230. Completed ink image 170
Is illustrated in FIG. The ink image 140 includes a plurality of ink pixels 110. After application of the polymer overcoat film 130 in box 220,
The fluid polymer overcoat film 130 polymerizes,
A transparent and solid polymer protective film 150 is formed on the ink image 140. To properly protect the ink image against fingerprints, oxidation and abrasion, the polymer protective film 150 needs to be continuous over the area of the receiver 80 that needs to be protected. At the same time, a strong chemical bond is formed between the polymer protective film 150 and the receiver 80. As is well known in the art,
The polymerization may occur by drying in air and / or with the aid of heating or radiation. The solid polymer protective film 150 is transparent for viewing the ink image. The polymer protective film 150 protected the ink image 140 on the ink receiver 80 with enhanced image durability. The printing of the ink image and the formation of the polymer protective film are shown terminated at box 240.

The thickness of the polymer protective film can be changed by controlling the thickness of the polymer overcoat film 130 as described above. In the present invention, it has been discovered that the polymer protective film 150 (FIG. 3) has an average thickness of at least 0.5 microns, preferably in the range of 1 to 10 microns, to provide adequate ink image protection. Was done. It has been discovered that sufficient gloss is provided by the smooth surface of the polymeric protective film achieved by the uniform ejection of the fluid ejection droplet 123 over the area of the ink image. The uniformity of the fluid overcoat film 130 can be enhanced by increasing the number of print passes over each area.

The polymer protective film 150 prevents physical abrasion and environmental contamination on the ink image. Therefore, the durability is improved. Fingerprints on the polymer film can be easily wiped off. Also, the chemical bonding between the film and the ink receiver can prevent the delamination problem associated with prior art laminated sheets.

[0029]

As described in detail above, according to the ink jet printing apparatus of the present invention, there is provided an ink jet printing apparatus for forming a durable ink image on a receiver in response to a digital image, comprising: a. A) at least one inkjet printhead adapted to eject ink to the receiver; and b) the inkjet print for ejecting ink to the receiver to form an ink image in response to the digital image. Means for operating the head; and c) fluid ejection means for applying a fluid on the ink image to form a transparent solid continuous film for protecting the ink image.

An advantage of the present invention is that the apparatus according to the present invention allows for the effective formation of polymer protective films at significantly reduced material and equipment costs.

Another advantage of the present invention is that lamination and related drawbacks can be eliminated by forming the polymeric protective film of the present invention.

Yet another advantage of the present invention is that the thickness and area of the polymer protective film can be controlled by computer and control electronics.

A feature of the present invention is that the polymer protective film is applied using an inkjet printhead in a post-printing step.

Another advantage of the present invention is that the application of the polymer overcoat film does not involve contact of the applicator with the ink image, reducing the likelihood of ink image disturbances.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an inkjet printing apparatus according to an embodiment of the invention.

FIG. 2 is a flowchart illustrating an operation of the inkjet printing apparatus of FIG. 1;

FIG. 3 is a cross-sectional view of a receiver having an ink image and a transparent solid protective film formed by the apparatus of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Ink-jet printing apparatus, 20 ... Computer, 25 ... Control electronic circuit, 30 ... Print head drive electronic circuit, 31, 32, 33, 34 ... Ink-jet print head, 40, 41, 42, 43 ... Ink container, 44 ... Fluid Container: 45: Holder, 54: Sliding rail, 55: Support member, 56: Belt, 57: Pulley mechanism, 60: Fluid ejection drive electronic circuit, 65: Roller, 70: Receiver transfer motor, 71: Print head translation motor 80, an ink receiver, 90, a platen, 100, an ink droplet, 110, an ink pixel, 123, a fluid ejection head, 125, an ejected polymer fluid droplet, 130, a polymer overcoat film, 140, an ink image, 150, Polymer protective film, 170 ... Completed ink image.

Claims (3)

[Claims] 1. An ink jet printing apparatus for forming a durable ink image on a receiver in response to a digital image, comprising: a) at least one ink jet adapted to eject ink to the receiver. A printhead; b) means for operating the inkjet printhead for ejecting ink to the receiver to form an ink image in response to the digital image; and c) means for protecting the ink image. An ink jet printing apparatus, comprising: a fluid ejecting unit for applying a fluid forming a continuous film of a transparent solid onto the ink image. 2. An inkjet printing apparatus for forming a durable ink image on a receiver in response to a digital image, comprising: a) at least one inkjet adapted to eject ink to the receiver. A printhead; b) means for operating the inkjet printhead to eject ink to the receiver to form an ink image in response to the digital image; and c) depositing a polymer fluid on the ink image. An ink jet printing apparatus comprising: a fluid ejecting means for applying; wherein the polymer fluid forms a transparent solid continuous polymer protective film for protecting the ink image. 3. An inkjet printing apparatus for forming a durable ink image on a receiver in response to a digital image, the method comprising: a) a first inkjet print adapted to eject ink to the receiver. A head and a second fluid ejection head for ejecting a polymer fluid to the receiver; b) moving the first ink jet print head and the second fluid ejection head simultaneously across the ink receiver. Means for causing the first inkjet printhead to eject ink to the receiver at different locations on the receiver to form ink pixels, and forming an ink image in response to the digital image. Means for forming said first ink-jet printhead and said first ink-jet printhead. Operating the second fluid ejection head for applying a polymer fluid on the pixel, the polymer fluid comprising means for forming a transparent solid continuous polymer protective film for protecting the ink image. An ink-jet printing apparatus, characterized in that: